Card and Miniature Collection Inventory Management

The collection inventory management is finally available.

It took quite longer than expected, mainly because I had to reorganize the code and did a bit of optimization and clean-up. For this reason small bugs may have been introduced so it would be nice if you all could play around a bit and try every portion of the site to report any problems you may find, no matter how small or unimportant.

It seems people are already adding items to their collections on the site, so hopefully it will become a useful and appreciated feature. And I also plan to improve it with checklists, binder-views, deck-availability checks, etc. (check the TO-DO section)